The Tokamak Fusion Test Reactor (TFTR) facility began operations with trace tritium in July 1993. These operations consist of the delivery, storage, injection, and subsequent processing of tritium gas in support of the D-T fusion program. The tritium is transferred throughout the facility using vacuum pumping systems and expansion volumes. These systems have manipulated and processed 14.4 PBq (388,983 Ci) of tritium from July 1993 through December 1994. This paper discusses the operational health physics program with regard to the performance of maintenance on tritium contaminated systems. Data and findings are provided from maintenance situations ranging from work on small volume piping to large volume neutral beam systems. Results and comparisons of tritium contamination levels, airborne radioactivity levels, and oil concentrations are presented for these systems. Descriptions of the maintenance tasks are provided for the entire scope of work and include general information toward conceptual understanding of the maintenance conduct of operations. General procedural requirements, job planning, pre-job briefing topics, control mechanisms, techniques to reduce exposure, and lessons learned are discussed. A complete description of various types of tritium monitoring and sampling equipment is also discussed. Several types of air monitoring equipment were used during these tasks to identify the most consistent and reliable methods for detection and radiological assessments. The results of radiological measurements are described in relation to the differentiation of elemental tritium to tritium oxide in worker's breathing zones and the associated general work area. A comparison is provided to process system monitoring, system moist air purges, system contamination levels and subsequent stack emission sampling for both elemental and oxide tritium. A summary is provided to describe the relationship between elemental and oxide tritium as a result of properly planned and performed maintenance on tritium process systems.